My advice, take it for what it's worth as a LEO that gives commands daily, keep it short, well heard and to the point.

STOP
SHOW ME YOUR HANDS
TURN AROUND
GET ON YOUR KNEES

I think you get the point, or at least I hope you do. There is no room for confusion, unless you don't speak english. In that case I can give you those same commands in spanish, any other language I need a translator.